The late Mark Wirtz (1943-2020) - a German-French songwriter-producer who found his biggest successes in England - is best-remembered for A Teenage Opera, an embryonic rock opera which inspired the likes of Pete Townshend and Paul McCartney and spawned Keith West's U.K. No. 2 single "Grocer Jack," a.k.a. "Excerpt from A Teenage Opera." Yet there was much more to Wirtz's discography than that lone hit and its parent project. Cherry Red's Strawberry imprint recently boxed up five discs of